Hardie plank siding – Hardie planks can be cut with a circular saw using a carbide blade or one specifically designed for cutting Hardie planks, but this method creates an excessive amount of dust. Lay your Hardie plank on a flat surface and align the straight edge where you want to make your cut. Hold the straight edge firmly to the surface of your Hardie plank. Use the knife to score along the straight edge, making a deep cut in 1/8 inch plate surface along the line to cut.
Hang Hardie board over the edge of the table with the marked line up and directly above the edge of the table. Press hard on the rim portion of the board, breaking the beam cleanly along the score you made. Install a carbide blade on your circular saw, or use a special diamond blade designed specifically for cutting Hardie plank siding and similar products. Mark a line with a pencil on the table where you want to make your cut.
Hang the board on the edge of a table or saw horses so that a sheet passing through the board along the score line does not cut into the table or saw horses. Wear a dust mask and goggles when cutting the Hardie plank siding. Do not force the saw blade through the material or it may chip or crack the board. Use a firm, smooth pressure on the sheet, allowing the saw and blade for cutting work.